Canvas Launcher

Infinite 2D home screen launcher for Android.
Pan. Zoom. Place apps and tools in a world, not in pages.

Why Canvas Launcher

Most launchers optimize for fixed pages and static icon grids. Canvas Launcher optimizes for spatial memory and flow:

• no page borders;
• no forced row/column lock;
• no context switch between "home pages".

Apps, notes, frames, and widgets live in one shared coordinate space you can navigate like a map.

Snapshot (April 5, 2026)

Metric	Current value
Gradle modules	12
Automated test files	74
Total test cases (@Test)	665
Unit test cases	649
Android instrumentation test cases	16
Aggregate instruction coverage (Jacoco)	81.69%
Min SDK / Target SDK	26 / 36
App version	1.0.0
Canvas widgets	5 implemented types

What Ships Today

Launcher core

• onboarding flow (DefaultActivity) with launcher-role request and fallback path;
• production HOME activity (MainActivity) with singleTask launcher behavior;
• package change receiver (PACKAGE_ADDED/REMOVED/CHANGED) with event bus propagation.

Infinite canvas interaction

• one-finger pan, two-finger zoom, world/screen coordinate transforms;
• minimap projection for spatial orientation at low zoom;
• viewport culling for large datasets;
• edit-mode drag with snap guides and edge auto-pan;
• gesture arbitration to reduce accidental mode conflicts.

Editing model on the canvas

• brush strokes, sticky notes, text blocks, frames;
• inline editing for text/title entities;
• move/resize/delete for editable objects;
• multi-select with computed selection bounds;
• undo stack for canvas-edit operations.

Widgets are already in production

Canvas widgets are not a placeholder state. The following types are implemented end-to-end (UI + state + persistence + tests):

• ClockDigital
• ClockAnalog
• Weather
• Notifications
• Calendar (today's events)

Related platform integration is wired:

• notification listener service for live notification feed;
• Android 13+ notifications permission handling;
• runtime calendar permission flow (READ_CALENDAR) for the Calendar widget;
• coarse/fine location flow for weather context.

App discovery and management

• direct app launch from canvas;
• searchable app panel with "show on canvas";
• uninstall action from in-app management flow;
• ranked search overlay with quick top-result launch;
• optional web fallback search from launcher input.

Smart layout strategies

• modes: SPIRAL, RECTANGLE, CIRCLE, OVAL, SMART_AUTO, ICON_COLOR;
• semantic grouping by app intent domain (communication, social, media, games, productivity, finance, etc.);
• vendor clustering for unknown semantic buckets;
• auto-generated labeled frames for semantic and color-based layouts.

Personalization

• theme modes: system / light / dark;
• 4 light palettes + 4 dark palettes;
• language modes: system, English, Russian, Spanish, German, French, Portuguese (Brazil).

Engineering Focus: Optimization Work Already Landed

• viewport culling in core:performance to avoid over-drawing offscreen app icons;
• cache stack for app icons: in-memory LRU + disk cache + batched preload + in-flight deduplication;
• predictable layout placement with collision-safe fallback search for dense app sets;
• modular dependency graph that keeps feature code isolated and testable;
• release build with shrinking/optimization enabled (isMinifyEnabled = true for release).

Architecture

graph TD
    A[app] --> D[domain]
    A --> FL[feature:launcher]
    A --> FC[feature:canvas]
    A --> FA[feature:apps]
    A --> CD[core:database]
    A --> CP[core:packages]
    A --> CS[core:settings]
    A --> CU[core:ui]
    A --> CM[core:model]
    A --> CC[core:common]
    A --> CPerf[core:performance]

    D --> CM
    D --> CC
    D --> CPerf

    FL --> D
    FL --> FC
    FL --> FA
    FL --> CP
    FL --> CPerf

    FA --> CD
    CP --> D
    CS --> D

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Module Guide

Module	Responsibility
:app	Activities, launcher role flow, settings screens, receiver wiring, app-level composition
:domain	Use cases, contracts, layout strategies, orchestration-level business logic
:feature:launcher	Main launcher presentation, tools overlay, edit orchestration, widget runtime
:feature:canvas	Infinite canvas rendering, gesture handling, drag and transform logic
:feature:apps	Apps data sources and repository bindings
:core:database	Room database, DAO APIs, entities, migrations, schema snapshots
:core:packages	PackageManager integrations, launch service, icon cache, package event bus
:core:performance	Camera math, coordinate transforms, viewport culling and minimap helpers
:core:settings	DataStore-backed preferences and mapping layer
:core:model	Shared cross-module models for app/canvas/ui state
:core:ui	Shared Compose theme system and reusable UI primitives
:core:common	Result/coroutine abstractions and common utilities

Quality and Test Coverage

Coverage and test counts below are generated from the repository state after local test execution on April 5, 2026.

Aggregate quality

• total instruction coverage: 81.69% (covered=52964, missed=11871);
• total test cases: 665;
• local connected smoke run: 16/16 instrumentation tests passed on device.

Coverage by module (instruction)

Module	Coverage
:domain	98.20%
:core:performance	98.21%
:core:model	95.21%
:core:ui	95.35%
:core:common	96.55%
:feature:apps	97.07%
:core:database	85.03%
:core:settings	80.78%
:feature:launcher	80.50%
:app	78.73%
:feature:canvas	76.69%
:core:packages	69.59%

CI

GitHub Actions workflow (.github/workflows/ci.yml) runs on pushes and pull requests to main, using JDK 21 and Android SDK setup, with the project test/build checks.

Run Locally

Prerequisites

• Android Studio (recent stable);
• Android SDK 26+;
• JDK 21 recommended.

Build debug APK

# macOS / Linux
./gradlew :app:assembleDebug

# Windows PowerShell
.\gradlew :app:assembleDebug

Run core test suite and coverage reports

# macOS / Linux
./gradlew :domain:test :core:model:test :core:performance:test :core:common:test :core:settings:testDebugUnitTest :core:database:testDebugUnitTest :core:packages:testDebugUnitTest :core:ui:testDebugUnitTest :feature:apps:testDebugUnitTest :feature:canvas:testDebugUnitTest :feature:launcher:testDebugUnitTest :app:testDebugUnitTest

# Windows PowerShell
.\gradlew :domain:test :core:model:test :core:performance:test :core:common:test :core:settings:testDebugUnitTest :core:database:testDebugUnitTest :core:packages:testDebugUnitTest :core:ui:testDebugUnitTest :feature:apps:testDebugUnitTest :feature:canvas:testDebugUnitTest :feature:launcher:testDebugUnitTest :app:testDebugUnitTest

Compute aggregate coverage summary (PowerShell)

powershell -ExecutionPolicy Bypass -File .\tmp_cov.ps1

Roadmap

• Infinite canvas launcher base
• Smart semantic layout presets
• Icon-color clustering presets
• Editable canvas objects (brush/notes/text/frames)
• Canvas widgets (clock/weather/notifications/calendar)
• Folders and advanced icon customization
• Backup/export/import of canvas state
• Macrobenchmark + startup/jank automation
• Optional cloud sync

Contributing

Contributions are welcome.

Start with:

• Contributing Guide
• Code of Conduct
• Security Policy
• Pull Request Template

High-impact contribution areas:

• interaction polish for dense-canvas workflows;
• accessibility and localization depth;
• higher coverage in core:packages and complex launcher UI branches;
• backup/sync architecture proposals.

License

Distributed under the MIT License. See LICENSE for details.